Safety switch-lock



A H. MACMINN AND w. H; GRAHAM.

` SAFETYVSWITCH LOCK. APPLlCATlON FILED M AY1|I920.

Patented Dec. `6, 192.1..

2 SHEETS-SHEET l.

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INVEN-roa, OMA Graham# ATTORNEY A. HJMACMINN AND w. H. GRAHAM. SAFETY SWITCH LOCK. APPLICATION FILED MAY15, 1920.

@HAHAHAHA erf Mii WITNESSES ATTO R N EY UNITED STATES PATENT OFFICE.

ALEXANDER H. MACMINN AND WILFORD H. GRAHAM, OF PORTLAND, MAINE.

SAFETY SWITCH-LOCK.

Application filed May 15,

To all fr0/tom t 'may concern:

Be it known that we, ALEXANDER I-I. MAC- MINN and lViLroRD I'I. GRAHAM, citizens of the United States, residing at Portland, in the county of Cumberland and State of Maine, have invented a new and useful Safety Switch-Lock, ofY which the following is a specification.

This invention refers to safety switch locks and its object is to provide a lock which may be attached to the arm of a switch stand to eliminate the necessity of the ordinary padlock and which may be opened either by means of a key or of a button, or the like, fast to the lock, the lattei` arrangement avoiding any liability o'f misplacing or losing parts. The lock is susceptible of at tachment to the switch stand in such manner that it may be used in Jfreezing weather without liability of encountering diticulties caused by accumulations of ice.

The invention is intended particularly for attachment to existing switch stands, requiring but a minimum of work to attach the lock and no material change in the working parts of the switch stand.

In accordance with the invention the lock is inclosed in a casing capable of being fixedly attached to the switch stand arm in position to receive the usual switch stand staple over which the arm engages and which staple is ordinarily used to receive a padlock holding the arm in the locked position. The lock is so constructed that the working parts are housed in the casing having an entrance and permitting the passage of the staple intothe casing so that the working parts of the lock are protected by the casing, which latter is so constructed that it may be entered by a key capable of actuating the lock bolt until the staple. has sufliciently entered the casing, whereupon the lock bolt will snap into locking engagement with the staple and can only be released by the withdrawal of the bolt. The only change in the ordinary switch lock installation found on the railroads is to produce a notch in the hasp to receive a lock bolt and to attach a lock casing with a lock mechanism therein to the switch arm so that the expense of applying the lock to the switch stands is but a minimum, the cost representing but little more than the cost of the lock mechanism itself.

The invention will be best understood from a consideration of the following detailed description taken in connection with Specification of Letters Patent.

Patented Dec. 6, 1921. 1920. serial No. 381,622.

the accompanying drawings forming this specification, with the understanding, however, that the invention is not confined to any strict conformity with the showing in the drawings, but may be changed and modified so. long as such changes and modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings: Y

- Figure l is an elevation of a switch standequipped with the invention.

Fig. 2 is an elevation of a switch lockVV with the inner face plate removed and some parts shown in section, the lock structure being indicated as in the locked position.

Fig. 3 is a section on line 3 3 of Fig. 2.

Fig. 4 is a section on the line 4 4 ofv Fig. 2.

Fig. 5 is a section Fig. 2. y

Fig. 6 is a view similar to Fig. 2 butA showing the parts in the unlocked or released positi'on. i

part of on the line 5-5 of Figs. 7, 8 and 9 are perspectiveviews or" details of the lock structure.

Referring to the drawings there is shown a switch sta-nd l includinga post 2 having an arm 3 pivoted thereto and a hasps4 adapted to traverse a passage 5 in the switch arm and project therebeyond. It is customary to provide the hasp or staple with an eye 6 for receiving a switch padlock and as it is the intention to apply the invention to existing switch-stands the eye may remain, although with the improved locking mechanism the eye has no function and would be omitted on new installations. The hasp, however, is slightly modified for use with the improvement forming the subject matter of this invention, by providing the hasp on one edge near the eye with a notch 7.

Applied to the arm 3 in covering relation to the passagel 5 is an elongated strip or plate 8 having a slot 9 therethrough, matching the passage 5 for the greater portion of the length of the passage and of suiicient extent to pass the hasp 4. Carried by the plate 8 is a casing 10 having a `crown portion 11 with one side in the form of a face plate 12 capable of being removed so as to expose the interior of thel casing 10, whereby to give access to the mechanism within the casing for adjustment or repair. In order to secnre the lockto the arm?) screws V13 tapped into the arm 3 may be used, the` screws being serviceable for fastening the plate 8 and casing 10 together and to the arm or other means Vmay be employed for the same purpose.

Near one end of the passage 9 the crown portion-11 of the casing 10 is provided with a partition 14 having terminal studs 15 set into the plate 8 vand the crown portion 11 respectively,` thus dividing the interior of the lock casing into two chambers 16 and 17 The partition 14is provided with a slot or passage 18 traversed by certain structures to be described. j

Located in most part within the chamber 16 and extended through the yslot 18 into the chamber 17 is a lock bolt 19 best `shown in Fig. 7. The lock bolt 19 comprises a block 20 with a recess 21 in one ed e, constituting the upper edge in the insta led position, and backed by an abutment lug 22 which, when the lock is assembled, is in the path of the web portion 23 of an ordinary switch-lock key 24 arranged to be introduced through a suitable opening in the face plate 12, which may be protected by a yieldable guard 25 onthe face plate 12. The key 24 is arranged to be received upon a. guide by a pin 26.

The bolt 19 is provided with a guiding stem 27 traversing an appropriate passage in the adjacent end wall of the crown portion 11 of the casing 10, while the other end of the bolt is formed witha nose 28 having progressive stepped portions constituting shoulders 29 and 30, beyond which latter there is provided a nose'31 with a rounded undersur'face 32 normally in the path of a rounded wall 33 on the hasp 4 and merging into the notch 7. The arrangement is such that when the hasp is introduced through the passage 9 the rounded end 33 will engage the rounded surface 32 of the nose 31 and push the lock bolt 19 out of the path of' the hasp until the notch 7 is reached, whereupon the nose 31 of the lock bolt will snap into the notch thus eti'ecting the locking. In order `to impart to the lock bolt a normal tendency to so snap into place, the lock bolt is furnished with a stud 34 carrying an intermediate coil portion of a spring 35 bearing at one end upon the inner wall of the casing crown 11.

' The forward extension of the nose portion 28 of the lock bolt has a cutaway portion36 on which there is mounted a pin 37 carrying a stepped block 38, shown separately in Fig. 8, and this block, which is of general angular conformation, has a shoulder extension 39 at one end anda nose 40 at the other with a rounded underface 41. The block 38is of such thickness as to tit the recess'36 substantially Hush with the thicker portion 20 of the lock bolt 19.

There is also provided a plate 42 having an angle extension 43 at one end, and a lug 44 at the other end near which the plate has a laterallyelongated slot 45 while the angle extension carries a pin 46. The plate 42 is also provided between its ends with a perforation 47 mounted on a pin 48 projecting from the bolt 19 near that end carrying the pin or extension 27. |The stud 34 on the bolt 19 is in the path of a shoulder 50 formed on the plate 42 adjacent to the angle eXtension 43, the shoulder 5() acting as a stop for limiting rocking movement of the plate 42 about its pivot 48.v The pin 46 is engaged by that end of the spring 35 remote from the end thereof engaging the inner wall of the casing. crown 11, this tending to rock the plate in one direction. The plate 42 is long enough to project through the slot 45 to an extent permitting the Vlug 44 to move in front of the partition 14 when the bolt 19 is projected into locking position with respect to the hasp 4, thus preventing anyV return movement of the lock bolt. The bloclr 38 is provided with a pin 51 engaged in the, slot 45, thereby permitting a limited rocking movement of the block 38 or of the plate 42 without the participation of the other with it. But as soon as yone end or the other of the slot 45 vand the `pin 51 are brought in engagement the plate 42 and block-38 move together and the one which is impelled causes movement of the other.

0n the bottom of the lock bolt 19 is a pin 52 engaged by one end 53 of a spring 54 having an'intermediate coil 55y surrounding a -pin 56 tast on the plate 8 andthe other end of the spring 54 is held by a pin 57 on the plate 8. VBy this arrangement the lock bolt is urged toward the looked position in addition to the tendency impartedto it by the spring 35; y

In order to furnish a supporting abutment for the face plate 12 and at the same time secure the face plate in position, screws 58 traverse the face plate and `are threaded into the opposite side fof the casing crown 11, and the screws are surrounded by sleeves 59 against which the face plate is `held by the screws, while the face plate is centered` in the crown portion 11 by the latter.

When the arm 3 is raised ior the purpose of releasingv the switch stand to turn it, the lock 'is out of engagement with the staple 4 and the switch stand may be turned from one position to another, as desired. When the proper positiono'f the switch is attained the arm 3 is lowered so that the staple 4 will pass through the arm and through the slot 9 into the compartment 17. In so doing the staple engages the nose 41 and by means of the pin 51 rocks the plate 42 until the lug 44 is free from engagement with the partition 14. By this time the staple has reached'the rounded edge 32 Aof the nose 3110i the lock bolt, and since the 111g 44 `no longer holds the lock bolt the latter is forced out of the path of the rounded portion 33 of the staple, being pushed through the slot 18 toward the chamber 16, the springs 35 and 54C yielding. As soon, however, as the notch 7 is reached the lock bolt and parts carried thereby snap into the recess 17 and thus hold the arm 3 against escape from the staple, this holding action continuing until the key 24 is introduced into the lock to purposely withdraw the bolt.

Since the easing l0 and its crown l1, together with the cover plate 25 effectively inclose the working parts of the lock there is no liability of water nding access to the lock and aiecting the saine during freezing weather.

There are conditions where it is not necessary to lock the switch stand against manipulation, as for instance, where the switch is used constantly, as would happen in a base switch yard. Under such circumstances a separate key need not be employed but the lock may be provided with a button readily manipulated from the outside of the lock to throw the lock bolt. When the switch is located elsewhere than in a base switch yard it is advisable to use a key to prevent unauthorized switch.

What is claimed is:

l. In combination with a manipulating arm having a passage therethrough, a lock casing on said arm over said passage, a partition within the casing at one side of said passage and having' a slot, a hasp or staple adapted to enter said passage at one side of the partition, a spring-actuated slidable lock bolt located in the casing at the other side of said partition and adapted to be projected through said slot to engage the hasp or staple, a plate pivotally mounted on said bolt and adapted to project at one end through said slot and having means for holding Said bolt in its locked position, and means for releasing said plate beore moving the bolt out of engagement with the hasp or staple.

2. In combination with a manipulating arm having a passage therethrough, a lock casing on said arm over said passage, a spring-actuated lock bolt in said casing, a hasp or staple to be engaged by said bolt, a plate pivotally mounted on said bolt and adapted to hold the bolt in its locked position, a spring for said plate, and means to permit suiiicient movement of said plate inmanipulation of the dependently of said bolt to release the bolt from its locked position before moving it out of engagement with said hasp.

3. The combination with a switch stand having a manipulating arm for the switch points and a hasp or staple positioned to traverse the arm, of a lock casing carried by the arm and entered by the hasp when the parts are in posit-ion to be locked, a lock bolt in the casing, a block pivoted on the lock bolt, and a plate having means for holding the bolt in the locked position and also pivotally mounted on the bolt, said lock and plate being provided with lost motion connections between them to permit suicient movement of the plate to release the bolt from the locked position before moving it out of engagement with the hasp.

4. The combination of a switch stand having a manipulating arm and a hasp or staple positioned to traverse the arm, of a lock comprising' a casing carried by the arm in position to receive the hasp, a lock bolt in the casing, a pivoted block carried by the lock bolt, a plate also pivotally mounted on the bolt and joined to the block by lost motion connections, a spring for the bolt within the casing and tending to move the bolt into locking engagement with the hasp, and a spring for the plate tending to move the latter into position to lock the bolt.

5. The combination with a switch stand having a manipulating arm and a hasp or staple positioned to traverse the arm, of a lock comprising a casing carried by the arm in' position to receive the hasp, a lock bolt in the casing, a pivoted block carried by the lock bolt, a plate having means to hold the bolt in the locked position and pivotally mounted on the bolt and joined to the block by lost motion connections` a spring for the bolt within the casing and tending to move the bolt into locking engagement with the hasp, and a spring for the plate tending to move the latter into position to lock the bolt, the hasp being bodily movable in a straightline into and out of locking position and the block and plate being rockable with lost nio* tion whereby to avoid interference with the bolt. In testimony that we claim the foregoing as our own, we have hereto aiiiaed our natures.

ALEX. H. li'IAoliIINN. VILFORD II. GRAHAM. 

